Use hook_og_links_alter() to remove content types from og group details block

As you can see from this major performace issue #330135: menu_router_build call in hook_init is a serious performance hit, the really roadblock is og_content_type_admin_menu_alter is not getting called by drupal machinery when we need. Any attempt to make this work seem to add signficant performance penalties. So I am thinking may be hook_menu_alter is not the hook we want to use.

I am a newbie when comes to dabbling in code. so ignore me if my thoughts don't make any sense.

At a fundamental level this module is about "removing" access to create certain content types in a given group. I mean without this module all content types can be created in a group (provided they are group enabled) and this module removed that access. So we can use og_links_alter to remove the links to create those types. Which links to remove that logic can be still same.
Now this removes the links visually. A user can still type in /node/add/create_node_type link and create content that way. To prevent that we could use hook_form_alter (or hook_form_FORM_ID_alter) and prevent the form being submitted for those content type for groups. Again the logic for which group prevents what will remain same.

Any thoughts?